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No. 625,942. Patented May 30, I899.

P. B. TRETHEWEY.

BOAT PBOPELLING MECHANISM.

(Application filed Feb. 1, 1899.) (No Model.) 2 Sheets-Sheet I.

Ea/R Z'aflewy lnvenfo r No. 625,942. Patented May 30,1899.

- P. n. TBETHEWEY.

BOAT PROPELLING MECHANISM.

(Appligation filed Feb. 1. 1899.) (No Model.) 2 Sheets-Sheet 2.

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UNITED STATES PATENT Orricr.

PAUL ROBINS. TRETI-IEWEY, .OF MUSKOKA FALLS, CANADA.

BOAT-PROPELLING M ECHANISM.

SPECIFICATION forming part of Letters Patent No. 625,942,'dated May 30, 189 9.

Application filed February 1,1899. Serial no. 704,203. (its model.)

To aZZ whom it may. concern.

Be itknown that I, PAUL RoBrNs TRETHE: WEY, a subject of Her Majesty the Queen of Great Britain, residing at Muskoka Falls, county of Muskoka, Province of Ontario, Ganada, have invented certain new and useful Improvements in Boat-Propelling Mechanisms; and I do hereby declare that the following is a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same My invention relates to improvements in boat-propelling mechanism. I

The object of my invention is to provide a simple and efficient means for propelling boats which will enable them to be moved at a greater speed with a less amount of power.

To these and other ends my invention consists in the improved construction and combination of parts hereinafter described, and

particularly pointed out in the appended claim. y

In the drawings, in which similar numerals of reference indicate similar parts in'all of the views, Figure l is a diagrammatic side elevation of a boat provided with my. improve? ments. Fig. 2 is a diagrammatic plan view of the same. Fig. 3 is a horizontal sectional view taken on the line 3-3 of Fig. 5. Fig. 4 is a vertical section taken on the line 4 at of Fig. 5. Fig. 5 is a rear end view of one of the conduit-channels, showing the relative arrangement of parts.

In the general method of boat propulsion as now practiced two disadvantages arise in the matter of speed, these consisting, first, in

the resistance'of the water through whichv the bow of the boat is'forced, and, second, in the formation of a vacuum at the stern, generally termed the wake.v These disadvantages result in the loss of a great amount of speed, requiring a greater amount of power to operate the propeller, the movement of which serves to increase the Vacuum. Many attempts have been made to remedy these de-' fects and alsoto remedy, in the case of canalboats, the wash. of the propeller, causing the banks to become affected; but these have proven unsuccessful owing to various causes. The present invention, however, is believed to remedy these defects by reducing the resistanceat the bow of the boat and preventing the formation of the vacuum entirely. or to a great extent. This is accomplished, primarily, by placing a channel or conduit or a series ofthem from end to end of the boat, the front'end allowing of the inlet of the water at the how. The water passes through the channel, drawn therethrough by means of a propeller or screw, and. passes out through the rear end, the passage of the water outward forcing the boat ahead. The propeller or screw being located in the channel, no churning of the water at the rear of the boat canensue, enabling canal-boats to pass along in the banks of the canal at greater.

speed.

To enable a better understanding of the principles to be had, I will now describe a construction shown in the drawings, which willillustrate the manner of operation.

The boat is provided with a central longitudinal channel 2, preferably circular, having its front end reduced, as shown at 3, but

opening out through the bow of the boat, the channel being preferably located along the keel. Near the rear end of the boat the channel is cammed upward, as at 4, leading to a A shaft 6 extends from the interior of the boat, where it. is connected to any suitable source of power-supply, and on said shaft is mounted a propeller or screw 7, having a periphery approximately of but slightly smaller size than that of the channel 5. This may, however, be varied, as the channel may be formed 'of a diameter several. times larger than that of the propeller. If desirable, similar channels may be located along the sides of the boat, as shown, where increased speed is desired.

The operation will be readily understood. The channels 2 and 5 being below the waterline of the boat, water will pass into the channel 2 untilit is filled. When the propeller is operated, the water in the channel 5 will be.

forced outward through the rear of the boat, forming a current through the channels 2 and 5, which carries the water from the bow of the boat through the boat and passes it out at the rear, causing the boat to move forward with decreased friction and the absence of the retarding effects of the vacuum.

The advantages are many and are thought to be obvious.

Vhile I have herein shown a preferred form of carrying my invention into effect, yet I do not desire to limit myself to such preferred details of construction, but claim the right to use any and all modifications thereof which will serve to carry into eifect the objects to be attained by this invention in so far as such modifications and changes may fall within the spirit and scope of my said in- Vention.

Having thus described my invention, what I claim as new is The combination with a boat having a channel extending from the front to the rear thereof, a portion of said channel being of smaller diameter than the remainder, a vertical oifset connecting the smaller and thelarger portions of said channel, of a propeller operatively mounted in the smaller portion of said channel adjacent to the said vertical oifset, and means for rotating said propeller, whereby the water is forced rearwardly through said channel for propelling the boat, substantially as described.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

PAUL ROBINS TRETIIEWEY. Vitnesses:

C. S. MAwDsLEY, THos. JoHNsoN. 

